I bought an experimental/ homebuilt airplane that has a turbocharger system in it that I am trying to identify the system. The airplane was built in 2003 and the builder has since died so this question is a challenge for the Old School guys out there.

Specifically I am trying to determine if the turbocharger bearing should have a fixed orifice in the oil inlet port of the turbocharger bearing to limit the amount of oil flowing through the turbocharger and if so what is the diameter of the orifice hole and where would it be located.

I ask because the engine is a Lycoming TIO-540 and it has only 170 hours on it and the oil pressure is fine when the engine oil is cool however when the oil temperature warms up the oil pressure is only 57 PSI at 2500 RPM (lower limit is 60 PSI) and 25 PSI when at idle (lower limit is 25 PSI and that is pretty for for this type of engine.

Here are some pictures however the logbook states that it is a "Aireasearch T4-GT with 1.5 L housing from Innovative Turbo Work Order 4957 and 5313"

The cast iron turbo housing has "A/R 1.52" and the aluminum housing has a logo that looks like a turbine with "ITS" cast into the aluminum.

THANKS FOR YOUR HELP!!!
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I think you're barking up the wrong tree, probably just because it's a new tree that you don't understand. You're saying that your hot oil pressure at 2500rpm is off by 5% and it's dead on at idle. Your first thought is the turbo? My first thought is the gauge! My second thought is: it's 3psi. 57psi at 2500 is a lot to use car guys that live on the 10psi per 1000rpm rule. To use, 25psi would be fine at 2500rpm.

 

Aviation plays by different rules, and it's common to ground a plane because a parameter is out of spec, the idea being if you can't hit the required number then something is wrong or going wrong and it doesn't belong in the air.

Be extremely careful. You want the utmost reliability in the air. I would measure the flow coming out of the turbo in a timed test, then plug the turbo oil line and remove the turbo to see if the engine can hit the number without the turbo in the loop.

 

After doing some reading on your engine it seems oil pressure is adjustable. You may be able to raise your pressure to spec.

https://www.lycoming.com/sites/default/files/MM-IO-360-P1A.pdf

 

Hi Guys,

THANKS AGAIN for the help!!!

My original post was somewhat lengthy so I left out a couple of details for brevity sake.

In troubleshooting the low oil pressure with this engine I did do the following:

-Verified that the oil pressure gauge was accurate
-Turned the adjusting screw in all of the way
-Drained the oil through a fine mesh screen and the screen was clean so no parts
-Cut open and inspected the oil filter paper element and no parts...completely clean
-Serviced the engine with fresh Aeroshell 100W PLUS oil (straight 50 weight)

So I really want to see if the oil system to the turbo is the culprit before I have to remove and disassemble the engine so if someone can help me identify what I am working with then hopefully I can do some additional research.

THANKS AGAIN!!!

 

Its been more than 10 years that I worked on a recep turbo injected opposed 540 lyco. I remember that we would shim the oil oressure regulator with washers to get the right oil pressure we needed at operating temps. Go to the local airfield and ask around for any maintence shop an they can get you in the right direction.

 

Based on the patina in the pictures I assume this thing has already flown some. If there wasn't a restrictor in it when you got it, there probably wasn't ever a restrictor in it. It seems unlikely that the seller removed a restrictor just to mess with you, look at other maintenance items.

 

It might be worth checking airboat forums as that’s a popular airboat engine also.

 

Assuming its a jb turbo, I can't think of a good reason that anyone would recommend a restrictor.... it's a bad idea for a land based vehicle.. Pull the inlet off the turbo, and measure radial, and axial play, if in spec, i'd be looking at a supply issue, or excessive leakage elsewhere.

 

ITS = Innovative Turbo Systems. They went out of business over 10 years ago. Supposedly some of the employees reopened the/a turbo business under the name Comp Turbo, which is still around. I have no idea if they kept or ever got the old ITS sales records, but you have the work order numbers so it might be worth giving them a call.

As far as I know, ITS used mostly older production Garrett wheels, so I would suspect the turbo is not a ball bearing unit. If that's the case, it should not have an oil restrictor. I might still have one of the ITS catalogs from the very late '90s.

 

Sorry I had to drop offline for a while...Life happens.

HANKS everyone for your help and advice!!!

>As far as I know, ITS used mostly older production Garrett wheels, so I would suspect the turbo is not a ball bearing unit. If that's the case, it should not have an oil restrictor. I might still have one of the ITS catalogs from the very late '90s. [/QUOTE]

65ShelbyClone

If you happen to find one of those cataloges somewhere if you can PLEASE make a copy of that page I would appreciate it!!!